Detecting behavior anomalies of cloud users for outlier actions

ABSTRACT

A method of detecting anomalous user behavior in a cloud environment includes receiving a vector that comprises counts of actions taken by the user during a current time interval; determining whether an action count in the vector is greater than a global mean; building a scale table by combining new action skills that are above a threshold and original action skills if below the threshold; and identifying outliers when the action count is greater than the global mean multiplied by a corresponding action scale from the scale table.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of the following U.S. Provisional Applications, each of which is incorporated herein by reference:

-   -   U.S. Provisional Application 62/835,980, titled DETECTING         BEHAVIOR ANOMALIES OF CLOUD USERS, filed on Apr. 18, 2019;     -   U.S. Provisional Application 62/835,993, titled ENTROPY-BASED         CLASSIFICATION OF HUMAN AND DIGITAL ENTITIES, filed on Apr. 18,         2019; and     -   U.S. Provisional Application 62/835,983, titled DETECTING         BEHAVIOR ANOMALIES OF CLOUD USERS FOR OUTLIER ACTIONS, filed on         Apr. 18, 2019.

This application is also related to the following commonly-assigned U.S. Non-Provisional Applications filed on the same date as the present application, each of which is incorporated herein by reference:

-   -   U.S. Non-Provisional application Ser. No. 16/750,852, titled         DETECTING BEHAVIOR ANOMALIES OF CLOUD USERS, filed on Jan. 23,         2020; and     -   U.S. Non-Provisional application Ser. No. 16/750,863, titled         ENTROPY-BASED CLASSIFICATION OF HUMAN AND DIGITAL ENTITIES,         filed on Jan. 23, 2020.

BACKGROUND

Cloud security involves the protection of customer data, applications, and infrastructures associated with cloud computing. Many aspects of security for cloud environments are similar to those for on-premises hardware and software. This is true for public clouds, private clouds, and/or hybrid clouds. Security concerns that are of particular interest in the cloud environment include unauthorized data exposure and leaks, weak access controls, susceptibility to attacks, availability disruptions, denial of service attacks, and so forth. However, instead of managing physical servers and storage devices, cloud security systems often rely on software-based security tools to monitor and protect the flow of information into and out of cloud resources. Therefore, cloud computing security IP may include a broad set of policies, technologies, applications, services, data, and other associated cloud computing infrastructures.

Security issues for cloud computing can be broadly segregated into two broad categories: (1) security issues faced by customers who host applications and store data on the cloud, and (2) security issues faced by cloud providers themselves. Security issues for cloud customers may aim to prevent user privilege escalation, which describes a situation where a cloud user is appropriated a limited set of permissions, but then escalates their activities beyond those permissions for malicious purposes, such as using insecure APIs, exploiting system and/or application vulnerabilities, using weak identities, infiltrating credential access management, and so forth.

BRIEF SUMMARY

In some embodiments, a method of detecting anomalous user behavior in cloud environments may include receiving a count of an action taken during a current time interval in a cloud environment; determining whether the count of the action is greater by more than a threshold amount than a statistical characterization of previous times when the action was taken across a peer group; determining whether the action represents an outlier; and generating an alert based on determining whether the action represents an outlier.

In some embodiments, a non-transitory computer-readable medium may include instructions that, when executed by one or more processors, cause the one or more processors to perform operations including receiving a count of an action taken during a current time interval in a cloud environment; determining whether the count of the action is greater by more than a threshold amount than a statistical characterization of previous times when the action was taken across a peer group; determining whether the action represents an outlier; and generating an alert based on determining whether the action represents an outlier.

In some embodiments, a system may include one or more processors and one or more memory devices including instructions that, when executed by the one or more processors, cause the one or more processors to perform operations including receiving a count of an action taken during a current time interval in a cloud environment; determining whether the count of the action is greater by more than a threshold amount than a statistical characterization of previous times when the action was taken across a peer group; determining whether the action represents an outlier; and generating an alert based on determining whether the action represents an outlier.

In any embodiments, any, none, or all of the following features may included inany combination and without limitation. The count of the action taken during the current time interval may include a count of a single action type performed by a single user. The count of the action taken during the current time interval may include a count of a single action type performed on a single resource. The method/operations may also include generating the count of the action taken during the current time interval by aggregating actions by a single user or on a single resource from an action log recorded during the current time interval. The threshold amount may include a predetermined number of standard deviations above the statistical characterization of the previous times when the action was taken across the peer group. Determining whether the count of the action is greater by more than a threshold amount may include providing the count of the action and a type of the action to a neural network; and receiving an output from the neural network indicating whether the action represents an outlier. The neural network may be trained using the count of the action, the type of the action, and a response to the alert. The method/operations may also include calculating a first vector that is representative of actions taken during a plurality of previous time intervals in the cloud environment; calculating a similarity between the first vector and a second vector that comprises counts of actions taken during a current time interval where the second vector may include the count of the action; comparing the similarity to a baseline threshold to determine whether one or more anomalous actions have occurred; and generating an alert based at least in part on a determination that the one or more anomalous actions have occurred in the cloud environment. The similarity may be calculated using a cosine similarity. Each entry in the first vector may include an average event score during the plurality of previous time intervals. Each of the plurality of previous time intervals may be one day. The plurality of previous time intervals may include a sliding window of days, where the sliding window of days may add the current time interval to the sliding window of days and may remove a least-recent time interval from the sliding window of days after each time interval. The first vector may be representative of actions taken during the plurality of previous time intervals by storing a histogram of event counts for each of the plurality of previous time intervals. Determining whether the action represents an outlier may include performing a second determination of whether the count of the action is greater than a global mean of action counts multiplied by a scale factor for the action. Determining whether the action represents an outlier may include calculating the scale factor as a ratio of a local mean of action counts over the global mean of action counts. Determining whether the action represents an outlier may include replacing an existing scale factor for the action when the scale factor is greater than the existing scale factor. The action may include a number of emails that are sent by a particular user. The action may include a number of folders created by a particular user.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of various embodiments may be realized by reference to the remaining portions of the specification and the drawings, wherein like reference numerals are used throughout the several drawings to refer to similar components. In some instances, a sub-label is associated with a reference numeral to denote one of multiple similar components. When reference is made to a reference numeral without specification to an existing sub-label, it is intended to refer to all such multiple similar components.

FIG. 1A illustrates a Cloud Access Security Broker (CASB) that can be used to identify behavioral anomalies in users for a number of different cloud customers, according to some embodiments.

FIG. 1B illustrates an alternate architecture for implementing the CASB in an Infrastructure as a Service (IaaS) system, according to some embodiments.

FIG. 1C illustrates some of the different configuration controls that may be monitored by the CASB, according to some embodiments.

FIG. 2 illustrates a diagram depicting how data is passed from a particular cloud environment to the CASB, according to some embodiments.

FIG. 3A illustrates actions taken by a particular user as stored and analyzed over time by the CASB.

FIG. 3B illustrates an example of a histogram memory that may be incremented by events, according to some embodiments.

FIG. 4 illustrates the average of the activity window in comparison to the current day, according to some embodiments.

FIG. 5A illustrates a flowchart for a method of detecting anomalous user behavior in a cloud environment, according to some embodiments.

FIG. 5B illustrates a flowchart for generating suspicious event scores, according to some embodiments.

FIG. 6A illustrates two data vectors describing user actions, according to some embodiments.

FIG. 6B illustrates a method for detecting individual outliers in comparison to a sliding activity window for a single object, according to some embodiments.

FIG. 7A illustrates equations that may be used to adjust a threshold based on a larger peer group, according to some embodiments.

FIG. 7B illustrates a flowchart of a method for detecting outliers, according to some embodiments.

FIG. 8 illustrates a simplified block diagram of a distributed system for implementing some of the embodiments.

FIG. 9 illustrates a simplified block diagram of components of a system environment by which services provided by the components of an embodiment system may be offered as cloud services.

FIG. 10 illustrates an exemplary computer system, in which various embodiments may be implemented.

DETAILED DESCRIPTION

Described herein are embodiments for detecting behavioral anomalies of cloud users by combining cosine similarity scores with cybersecurity domain expertise. As tested in a production cloud environment, this technique is capable of detecting behavioral anomalies of cloud users without any labeled data sets. This unsupervised machine learning approach does not require a priori knowledge of normal and/or abnormal behaviors or actions. This approach also does not require user information such as privilege level, job function, or action permissions. This approach is designed to successfully detect (1) cloud users' abnormal actions, including user privilege escalation behaviors, and (2) excessive privilege actions across all cloud tenants in various cloud applications or services. As described in greater detail below, a peer group analysis may be employed to identify behavioral anomalies.

FIG. 1A illustrates a Cloud Access Security Broker (CASB) 100 that can be used to identify behavioral anomalies in users for a number of different cloud customers, according to some embodiments. The CASB 100 is a cloud service that may provide visibility into an entire cloud stack and serve as a security automation tool. The CASB 100 may provide real-time continuous monitoring of activity across the plurality of different cloud environments simultaneously. This may include monitoring configurations and transactions that identify behavioral anomalies and patterns of fraud or breach across cloud applications. A set of security policies can be used to discover and prevent unwanted actions on sensitive content in cloud environments. These security policies allow administrators to configure the CASB 100 to audit, alert, encrypt, and/or quarantine content in real time in response to detected security threats. In addition to detecting threats, the CASB 100 may also be configured to predict and visualize security threats before they occur by providing a dashboard that shows current activity along with predicted trends in activity. Once anomalies are detected by the CASB 100, the system can take action and conduct forensics to isolate, analyze, and contain known security threats.

The CASB 100 may monitor a plurality of different cloud environments. For example, the CASB 100 may interface with the Oracle Cloud Infrastructure® (OCI) 102 that can provide compute instances, networking, data storage, databases, cloud interconnections, edge services, load-balancing, governance policies, data streaming, resource management, and other cloud-based services. Additionally, the CASB 100 may also interact with other cloud environments, such as Oracle's Human Capital Management® (HCI) 104 suite, Amazon Web Services (AWS) 108, Microsoft Office 365 (MSO365) 106, and/or the like.

To monitor these different cloud environments, the CASB 100 may be configured to receive real-time data monitoring streams for thousands of individual users. Assuming that there are Q different cloud environments being monitored by the CASB 100, and each of the Q environments includes N tenants, this may provide the simultaneous monitoring of Q×N tenants. Furthermore, if each tenant has at least M users, the CASB 100 may simultaneously monitor at least Q×N×M users.

FIG. 1B illustrates an alternate architecture for implementing the CASB 100 in an Infrastructure as a Service (IaaS) system, according to some embodiments. In contrast to FIG. 1A, this architecture places the CASB 100 within the infrastructure of a particular cloud service. With the CASB 100 as part of the infrastructure, the CASB 100 may have more access to specific types of actions that take place within the infrastructure.

For example, in the multi-cloud environment of FIG. 1A, the CASB 100 monitored events that occurred at the application level in each of the different cloud environments. In the infrastructure-based architecture of FIG. 1B, the CASB 100 may instead receive events that occur at the resource level. For instance, the CASB 100 may receive events that occur related to specific compute objects 130 within the infrastructure. The CASB 100 may also receive events that occur in relation to specific network objects 132 within the infrastructure. Additionally, the CASB 100 may receive events related to specific storage objects 134 within the architecture. This architecture allows the CASB 100 to monitor events that occur as resources are provisioned, initialized, used, or otherwise interacted with by a specific user. It additionally allows the CASB 100 to monitor events based on users, resources, applications, objects, and/or any other entities in the infrastructure. Therefore, events that are monitored on a per-user basis are used merely by way of example in this disclosure. Any of the techniques described below for monitoring events on a per-user basis may also be monitored on a per-resource basis. For example, events may be monitored for a particular compute object. When the compute object generates an event score that indicates a malicious anomaly, the compute resource may be shut down or other remedial action may be taken to minimize a perceived threat against the resource. Table 1 illustrated below lists some of the cloud infrastructure controls that may be monitored by the CASB 100.

TABLE 1 Activity Control Compute Tier 1, should be enabled as is-Alerts when compute Images- images are imported or updated. Changing the compute Import images is normally performed or Update during an update or upgrade to the image, e.g., Image patches to the OS. However, malicious users can change an image that would affect every compute instance launched from the image, compromising the integrity of the instance. Database Tier 1, should be enabled as is-Alerts when database Systems- systems are terminated or updated. Altering database Update systems may indicate a ransomeware attack. It may also or Terminate affect the integrity and availability of the data and may Database release sensitive data. System Identity Tier 1, should be enabled as is-Alerts when users are Group- added to groups. Sensitive groups, such as the admin Add User group, should be named in the Resource Name in order to alert when users are added to it. This policy has been configured with the resource name of CASB_SERVICE_ACCOUNT_GROUP which allows all users to read all information in the tenant. If you registered the cloud to CASB with a different group name, ensure consistency by changing the resource name in this policy. Identity Tier 1, should be enabled as is-Alerts when policies are Policies- created, deleted. or updated. Changing policies will Create impact the all users in the group and may enable Delete or entitlements to users who do not need them. Update Policy Networking Tier 1, should be enabled as is-Alerts when Virtual Cloud Virtual Cloud Networks are created. Creating or updating a VCN can Networks- allow external connections to corporate resources Create or and data. Update VCN Object Tier 1, should be enabled as is-Alerts when a pre- Storage- authenticated request is created for access Create to object storage. Pre-authenticated requests Pre- provide a way to let users access a bucket or an authenticated object without having their own credentials, Request as long as the request creator has permissions to access those objects. Access to object storage without requiring authentication impacts data confidentiality. Storage Block Tier 2, may require modification for production services- Volumes- Alerts when storage block volumes are created, attached, Block detached or deleted. Volume Changes Compute Tier 2, may require modification for production services- Images- Alerts with compute images are exported. Export Image Compute Tier 2, may require modification for production services- Instance- Alerts when compute instances are launched. ENSURE Launch that contextual configurations are used BEFORE enabling Instance this alert. As a safeguard to accidentally enabling this policy, the USERNAME context filter is set to \@company.com\” to prevent uncontrolled alerting-this configuration may be modified to trigger this alert.” Compute Tier 2, may require modification for production services- Instance- Alerts when compute instances are terminated. ENSURE Terminate that contextual configurations are used BEFORE enabling Instance this alert. As a safeguard to accidentally enabling this policy, the USERNAME context filter is set to \@company.com\“ to prevent uncontrolled alerting-you will need to modify this configuration in order to trigger this alert.” Compute Tier 2, may require modification for production services- Instance- Alerts when compute instances are updated. Update Instance Database Tier 2, may require modification for production services- Systems- Alerts when Database systems are launched. Launch Database System Identity Tier 2, may require modification for production services- Group- Alerts when users are removed from groups. Remove User Identity Tier 2, may require modification for production services- Groups- Alerts when identity groups are created or deleted. Create or Delete Group Identity Tier 2, may require modification for production services- Users- Alerts when customer secretKeys, passwords or swift Create or passwords are created, deleted, updated or Delete reset (passwords only). Credentials Identity Tier 2, may require modification for production services- Users- Alerts when users are created or updated. ENSURE that Create or contextual configurations are used BEFORE enabling this Update User alert. As a safeguard to accidentally enabling this policy, the USERNAME context filter is set to \@company.com\“ to prevent uncontrolled alerting-you will need to modify this configuration in order to trigger this alert.” Identity Tier 2, may require modification for production services- Users-List Alerts when customer API keys, customer secretKeys or credentials swift passwords are listed. Identity Tier 2, may require modification for production services- Users-Login Alerts when users login successfully or fail login. Fail ENSURE that contextual configurations or Success are used BEFORE enabling this alert. As a safeguard to accidentally enabling this policy, the RESOURCE NAME is set to CASB_SERVICE_ACCOUNT or ADMIN to prevent uncontrolled alerting-you will need to modify this configuration in order to trigger this alert. Identity Tier 2, may require modification for production services- Users- Alerts when API keys are uploaded or deleted. Upload or Delete API Key Networking Tier 2, may require modification for production Load services-Alerts when listeners are created or Balancers- deleted. A listener is a logical entity that Create checks for incoming traffic on the load Update balancer's IP address. or Delete Listener Networking Tier 2, may require modification for production services- Load Alerts when load balancers are created or deleted. Balancers- Create Update or Delete Load Balancer Networking Tier 2, may require modification for production services- Virtual Cloud Alerts when Virtual Cloud Networks are created. VCNs Networks- can allow external connections to corporate resources and Delete VCN data. Deleting them disable functions or contribute to complete loss of service. Object Tier 2, may require modification for production services- Storage- Alerts when a storage bucket is created or updated. Create or Update Bucket

In some embodiments, the architecture in FIG. 1B may also cover the resource-configuration level of events. For example, a bucket instance may be created in which certain objects or resources may be stored in the architecture. When an action is taken relative to that object or resource in the bucket (e.g., initialization, use, deletion, etc.) an event may be generated that can be compared to a known baseline for that event as described in greater detail below (e.g., industry baseline, per-user baseline, per-tenant baseline, etc.). This also allows the CASB 100 to monitor the state of individual resources. For example, if a bucket object is created and remains in a particular state for predetermined time window (e.g., 90 days), the state itself may be monitored and compared to predetermined baselines. Additionally, state changes may be monitored and compared to baselines and thresholds as described below.

FIG. 1C illustrates some of the different configuration controls 160 that may be monitored by the CASB 100, according to some embodiments. Configuration controls 160 monitor configurations and states or specific resources that may generate events when the control conditions illustrated in FIG. 1C are met. For example, an alert may be generated when a load balancer SSL certificate expires within the next 45 days. In another example, an alert may be generated when KMS keys have not been rotated within a predetermined expiration interval. In another example, an alert may be generated when a group of administrators has more members than a predetermined threshold. Each of these configurations illustrated in FIG. 1C may be monitored and used to generate alerts as illustrated.

FIG. 2 illustrates a diagram depicting how data is passed from a particular cloud environment to the CASB, according to some embodiments. In this example, a particular environment, such as the OCI environment 102, may periodically pass an activity table 202 to the CASB 100 for analysis. The OCI environment 102 may be one of many cloud environments that is monitored simultaneously by the CASB 100 as illustrated in FIG. 1A. Alternatively or additionally, the OCI environment 102 may be part of the same IaaS architecture as the CASB 100 as illustrated in FIG. 1B. The activity table 202 may include a plurality of activity vectors or data rows that describe actions taken by particular users. Each row or vector may include a tenant ID, a user ID, a time, and/or an action taken, along with other data related to a particular action. For example, the activity table 202 includes a first row 204 for a “Send Email” action. This action took place at 12:34:56 PM and was executed by user #12442 in the cloud environment of tenant #10002. Each row in the activity table 202 may represent a single action, therefore the activity table 202 may include many thousands of entries over a time window to describe all of the actions for each user.

The data table 202 may be sent periodically from the environment to the CASB 100 at different intervals. For example, some embodiments may store a list of actions at the environment 102 for a predetermined time interval, such as one hour. At the expiration of the predetermined time interval, the list of actions may be transmitted together as the activity table 202 to the CASB 100, such that the CASB 100 receives a new batch of actions to analyze every hour. Some embodiments may stream rows in the activity table 202 continuously over time. In these embodiments, the CASB 100 may receive rows in the activity table 202 continuously in real time as they are generated at the environment 102. Software applications such as Cassandra® or Kafka® may be used to stream these data to the CASB 100. Some embodiments may periodically transmit batches of rows to the CASB 100 during normal operating conditions, and dynamically adjust the frequency with which transmissions are made based on analysis results of the data at the CASB 100. For example, the activity table 202 may be transmitted once per hour until a serious behavioral anomaly has been detected for one of the users. After detecting the anomaly, the time interval between transmissions of the activity table 202 may be shortened by, for example, 50% to transmit every half hour. In another example, a default time interval of one hour may be lengthened after a predetermined time interval during which no anomalies were detected. Some embodiments may transmit rows in the activity table 202 when a predetermined number of rows have been accumulated at the environment 102. For example, data rows may be stored at the environment 102 until 100 such rows have been accumulated. At this point, the 100 rows can be transmitted in the activity table 202 to the CASB 100.

It should be noted that the data in the activity table 202 need not be labeled. In other words, no single row needs to be labeled as being “normal” or “abnormal.” Instead, the CASB 100 only receives an indication that an action was taken without any characterization of whether that action should be allowed or not. Furthermore, the CASB 100 need not receive any information from any of the cloud environments in the form of criteria or guidance as to which action types should be allowed, what privilege levels are operative in those environments, or how anomalies should be detected. The cloud environment simply transmits a list of actions to the CASB 100, and then relies on the CASB 100 to identify anomalies without any additional information. This process is complicated by the large number of tenants and users that may be monitored across the world.

The embodiments described herein overcome these challenges by detecting behavioral anomalies of all cloud users and formulating user peer groups to classify behaviors as abnormal. This new method may combine cosine similarity scores of cloud users' behaviors with an internally generated scoring system for certain activities. These methods may be described as unsupervised machine-learning methods, as no labeled inputs or training data sets need be required. This may be described as a machine learning algorithm that uses the cosine similarity score as an input to a model representing different baselines and thresholds to generate an “abnormal” and/or a “normal” output for each user, event, vector of events, and so forth.

Peer group analysis includes the process of categorizing a user by his or her personal and/or digital traits. In this cloud security environment, this includes active directory attributes (i.e. title, job function, business unit, manager, etc. . . . ), types of permissions allocated to a user in a given cloud application/service, his or her geographical locale(s), his or her relationship to the company (contractor, employee, etc. . . . ), a human vs. bot relationship, and so forth. The typical relation between a user and a peer group is 1:N (i.e. a single person can be associated with an undetermined amount of peer groups). Different peer groups may be assigned for generating thresholds and baselines as described below. Any and all of these peer groups described above may be used in calculating such baselines and thresholds.

The process of privilege escalation can be defined as a user who is legitimately appropriated a limited set of permissions, and in some form is granted and leverages an escalation in privileges for malicious purposes. Internal and external bad actors may use privilege escalation via insecure APIs, system/application vulnerabilities, weak identity, credential access management, and/or malicious insiders to complete some pre-planned objective. Internal bad actors may use privilege escalation using normal credentials, but performing actions that exceed the permissions allowed by those credentials.

The peer group analysis is the process performed by some embodiments of using a historic data set to make intelligent assumptions about a particular user. For example, the system may determine the a priori actions of a particular user as a means for categorizing a user as an administrative or non-administrative user. A score table may be created after the respective resource action pairs are ranked by relative privilege and stored as a labeled dataset for machine learning and data science models related to privilege escalation as described below. Actions can be effectively ranked by using a cloud application and/or service default IAM standards/policy as a means to categorize a privilege level required to complete a specific cloud event. For example, in OCI there is the standard that creating and/or editing policies may require administrative permissions because they dynamically assign management permissions to both individuals and/or groups. In another example, out-of-the-box permissions may provide some actions exclusively to a unique tenant root administrator in AWS.

The CASB 100 may receive lists of actions executed by particular users as described above. The CASB 100 may then store and analyze each of these actions on a per-user basis. FIG. 3A illustrates actions taken by a particular user as stored and analyzed over time by the CASB 100. For example, the actions illustrated in FIG. 3 may be associated with user # 12442 from FIG. 2 . A first time interval may be used for generating a set of histograms 300 of actions that are taken during the first time interval. For example, the first time interval may be a single day, such that all instances of each action are aggregated together for each day. The bins in the histograms 300 may represent separate activities. Thus, when a new activity record is received, the memory bin for that activity may be incremented. When a new day begins, a new array of memory locations for the new day's histogram may be allocated or reset, with each memory location representing a bin for a specific user action. When actions are received during the new day, the new memory locations may be incremented and the previous memory locations may remain unchanged as a historical record of the previous day's actions.

In FIG. 3A, each vertical column represents a histogram of user actions taken on a particular day. Each of the horizontal rows represents bin in the histogram 300 for each day. For example, on Day 1, user # 12442 may have sent 22 emails, while on Day 2, user #12442 may have sent 25 emails. Note that because these values are stored in bins of the histograms 300, the particular times at which these emails were sent need not be stored. Instead, only the action bin for that day needs to be incremented to show that the action took place. In other embodiments, different time intervals may be used, such as every 1 hour, 2 hours, 6 hours, 12 hours, and so forth. Additionally, some embodiments may use different histograms for daytime hours versus nighttime hours, as well as weekdays versus weekends.

Histograms 300 may include histograms for a number of different time intervals. For example, some histograms 300 may include histograms for 90 days, 120 days, 30 days, 45 days, and so forth. Some embodiments may use an analysis window 306 that selects a number of previous days' histograms for comparison to the histogram for a current day 308. Some embodiments need not store histograms for every time interval in the analysis window 306. Instead, these embodiments may combine the histograms for the time intervals in the analysis window 306 into a single histogram that is representative of all of the time intervals. For example, some embodiments may average the values in each bin of the histograms for the time intervals in the analysis window 306 for comparison to the current date 308.

For example, the analysis window 306 may include a sliding window of 90 days used for comparison with the current day 308. The actions taken over the 90 days in the analysis window 306 may be averaged together to generate a single average histogram that is representative of the previous 90 days. On the next day, the average value can be recalculated by subtracting out the action counts of the oldest day in the analysis window 306 and adding the actions of the current date 308. The length of the analysis window 306 may include any number of days, such as: 14 days, 21 days, 30 days, 45 days, 60 days, 75 days, 90 days, 120 days, six months, one year, and so forth. The lengthy analysis window may also include ranges of days, such as at least 14 days, at least 30 days, at least 45 days, at least 60 days, at least 75 days, at least 90 days, between 14 days and 30 days, between 30 days and 45 days, between 45 days and 60 days, between six months and one year, at least one year, between one year and two years, and so forth.

FIG. 3B illustrates an example of a histogram memory that may be incremented by events, according to some embodiments. In this example, an analysis window of 90 days is used merely by way of example. The 90 day window 354 may include a memory location for each event on each time interval in the 90 day window 354. For example, each day may include a memory location corresponding to each event.

To record new events in a current day, a number of different methods may be used to receive and process incoming events. In some embodiments, the system may periodically receive a log 360 that includes a list of events that have been triggered by various users, resources, applications, and so forth. The log 360 may be parsed to identify specific users/resources associated with each event. The histogram memory for the associated user/resource may then be identified and for each event that is recorded in the log 360, and an event counter stored in the memory location for that event on that day may be incremented. A simple increment function 364 may be used to increment the value of the memory location with each event processed.

In some embodiments, the system may receive a real-time event stream 362 that is received as the events are generated by the system. This may be used particularly in the IaaS architecture of FIG. 1B described above. Memory locations may subscribe to particular event streams for resources, users, and/or event types. When new events are received, they can be channeled to the specific memory location to increment an existing value. The value incremented may be a set of registers representing a current date 358.

The 90 day window 354 may be processed at the end of each interval (e.g., at the end of each day) to calculate an average for the current 90 day window 354. An averaging function 366 may aggregate the event totals for each of the days in the histogram memory for each event type. The averaging function 366 may then divide this aggregate by the length of the 90 day window 354 to generate an average value 356 for each event type. The average value 356 may then be compared to the event count for the current day 358 to generate real-time alerts as the events are processed. As described above, some embodiments may subtract a last day 352 shifted out of the window (e.g., the 91^(st) day) and add the most recent day to a current average value 356. This may minimize the mathematical operations performed by the system when aggregating a large number of days in the 90 day window 354.

Upon moving to a subsequent time interval, such as moving to the next calendar day, the system may shift the values from the current date 358 into the 90 day window 354 and reset the values for the current date 358. The system may also update the average value 356 for the previous 90 day window by subtracting the 91^(st) day 352 and adding the current date 358 divided by the length of the 90 day window 354.

FIG. 4 illustrates the average of the activity window 408 in comparison to the current day 308, according to some embodiments. As described above, average of the activity window 408 may be calculated by aggregating the values in each of the time bins for each of the daily histograms for each action type. This value may then be divided by the length of the analysis window 306 to generate the average values illustrated in FIG. 4 . Anomalies can then be detected in part by comparing the average of the activity window 408 with the action counts of the current date 308. As used herein, the terms “action” and “event” may be used interchangeably. Actions may refer to specific actions taken by users or against a particular resource, while events may represent generated indications of those actions. However, this disclosure and the claims may use these two terms interchangeably.

Various statistical methods can be executed to compare the average of the activity window 408 to the actions of the current date 308. Some embodiments may calculate the Euclidean distance between each entry. Other embodiments may calculate the Hamming distance. The embodiment of FIG. 4 treats the histograms for the average of the activity window 408 and the current day 308 as data vectors. This example then calculates the multidimensional cosine value between the two vectors 402, 404 as an estimate of their similarity. This calculation may include calculating the dot product of the two vectors and dividing the result by the product of the magnitude of the two vectors. A first vector may be representative of actions taken during a plurality of previous time intervals, such as the average of the analysis window described above. A second vector may include counts of actions taken by a particular user, on a particular resource, using a particular application, and so forth, during a current time interval, such as during a current day. A sample equation 406 is illustrated in FIG. 4 . Pseudocode for calculating the similarity of the two vectors is illustrated below.

  from sklearn.metrics.pairwise import cosine_similarity dfC = dfM.groupby([′evntactor′, ′evntaction′]).apply(lambda g: cosine_similarity(g[′count_x′], g[′count_y′])) df = pd.DataFrame(cosine_similarity(v3[:, 1:], v4[:, l:])) def cos_sim(a, b):  dot_product = np.dot(a, b)  norm _a = np.linalg.norm(a)  norm _b = np.linalg.norm(b)  return dot_product / (norm _a * norm_b) import numpy as np  def cosine(a, b):  return np.dot(a, b.T) / (norm2(a) * norm2(b))

Calculating a measure of similarity between the two vectors 402, 404 can be used to characterize anomalies in the behavior of the user on a day-to-day basis. Stated another way, if the activities taken by user on the current day are significantly different than the average activities taken on a previous day, then this may represent anomalous behavior. This characterization may be made without knowing whether the individual actions are allowed to be executed by the user or not. Users are typically granted a set of permissions or privileges referred to herein as a “privilege level.” A user's privilege level will allow them to take certain actions without consequence. However, “privilege escalation” occurs when a user takes an action that is above that which is allowed by their privilege level. However, the CASB 100 does not know the privilege level of each user, and does not know which actions are associated with each privilege level. Therefore, the CASB 100 uses this comparison of current user actions with previous user actions to identify actions that may indicate the user is doing something outside of their permission level. This operates on the assumption that users do not operate outside of their privilege level excessively over time without being caught by the particular cloud environment for the customer. The CASB 100 can identify and flag such behavior before it becomes a pattern or excessive enough to trigger most internal customer cloud controls. The result may be characterized as a similarity between the first vector and the second vector.

FIG. 5A illustrates a flowchart 500 for a method of detecting anomalous user behavior in a cloud environment, according to some embodiments. At step 502, an average action histogram may be calculated for an activity window, such as an average event score for each type of action occurring in previous analysis window. This may be calculated by receiving and processing events that are specific to users, resources, applications, and/or other objects/entities in one or more cloud environments. The system may monitor many cloud environments simultaneously as depicted above in FIG. 1A, or may be part of an IaaS cloud infrastructure as depicted above in FIG. 1B. The average event score may be calculated by aggregating the event scores from each individual time interval within the analysis window and dividing it by the length of the window. In other embodiments, different statistical methods may be used to generate an event score in addition to an average score. For example, some embodiments may use a median value or a mode value. Some embodiments may remove various outliers that go beyond a threshold of the average when calculating the event score. In some embodiments, event scores from some days in the analysis window may be more heavily weighted than those of other days (e.g., events occurring on a weekend may be more likely to be suspicious than events occurring on a workday). In some embodiments, this event score for the analysis window may be generated at the end of each interval in the analysis window (e.g. at the end of each day) such that it can be compared continuously to events as they occur on the next day. The analysis window may be a sliding window where values in the histogram drop off a rear edge of the window as new values are added to an opposite end of the window as depicted in FIG. 3B above.

At step 504, the similarity between the average event score for the activity window and the event score of the current day can be calculated. This similarity may include the cosine similarity function described above. However, the cosine similarity is used only as an example and is not meant to be limiting. Other embodiments may use other similarity measures or similarity functions to calculate the similarity between the average event score and a current event score. Some embodiments may use a Euclidean distance or a Manhattan distance. Some embodiments may use a Minkowski distance. Some embodiments may use a Jaccard similarity. In short any similarity measurement may be used when comparing these two values.

At step 506, the similarity score can be compared to a baseline threshold to classify the user behavior as anomalous. The baseline threshold may represent a minimum threshold for evaluating the event score for a current day. For example, crossing the baseline threshold may represent an initial indication that an anomaly has taken place for this type of event for this user/resource/application, etc. This baseline threshold may be calculated using a number of different methods. In some embodiments, the baseline threshold may be calculated as a predetermined statistical difference from the event score for the activity window. For example, a baseline threshold may be a number of statistical deviations away from the average value of the activity window based on the average value calculation. In some embodiments, the baseline threshold may be calculated using average values that are aggregated across a user, across a particular tenant, across users in an industry, across users monitored in multiple cloud environments by the system, and/or any other peer group described above for peer-group analysis. However, in these embodiments, the “peer group” may include actions from the same user or against the same resource performed in a previous time interval. Therefore, the “peer group” may include actions taken by the same user in the sliding activity window described above.

In some embodiments, the baseline threshold may be dynamically calculated and adjusted using a machine learning algorithm. For example, the machine learning algorithm may include a neural network that receives the event scores for the event scores for the current day and for the activity window. The neural network may also receive the similarity score calculated between these two event scores. The neural network may then output an indication of “normal” or “abnormal.” The baseline threshold represented by the neural network may be adjusted over time as data is continuously provided to the network and used to train the network. For example, when an alert is generated, a response to that alert may be used as a training input to determine whether the corresponding output of the neural network was correct (e.g., did the alert generate a responsive action or was it suppressed?).

Some embodiments may stop the analysis here and simply report the anomalous behavior to the customers cloud environment. However, some embodiments may perform further analysis steps to better classify the anomalous behavior as acceptable anomalous behavior or unacceptable anomalous behavior. Specifically, some anomalous behavior may not be of concern, and instead may simply be behavior that is not often executed by most users. For example, a first privilege level, such as a user privilege level, may allow users to set an acceptable domain. This action may be allowed at the user privilege level, but may only be executed rarely, such as once a month. Therefore, every execution of this action may appear to be anomalous, while still being entirely acceptable to the customer cloud environment.

The method may also include determining whether the anomaly exceeds an upper threshold (510). The upper threshold may be calculated in a manner similar to how the baseline threshold was calculated as described above. The upper threshold may characterize an event score as definitely unauthorized. These two thresholds together allow for a robust characterization of event scores. As an event score climbs above the baseline threshold, the event goes from being characterized as benign to being at least suspicious. As that event score continues to climb towards the upper threshold, suspicion may increase regarding that event score. When that event score finally crosses the upper threshold, an alert may be generated (512) to indicate that the event score represents a known anomaly related to that user, resource, application, and/or other object.

For event scores that fall between the baseline threshold on the upper threshold, additional processing may be performed to determine whether a suspicious event score should generate an alert. FIG. 5B illustrates a flowchart 550 for generating suspicious event scores, according to some embodiments. Flowchart 550 may be a continuation of flowchart 500 described above. To further refine the process, some embodiments may generate and/or access an internal score table that provides a numerical score for each action in the action histograms. For example, the scores may range between 1 and 100. The higher the score, the higher the assumed privilege level may need to be for the action to be allowed. For example, sending an email may have a score of 2, while instantiating a new company entity may have a score of 95. In general terms, the score for anomalous actions may be used to classify the anomalous action as normal or abnormal.

Continuing with flowchart 500, at step 520, a score database may be accessed. The score database may include a list of activity scores that indicate a perceived severity of the action relative to other actions. Using the similarity measurement described above only compares the frequency with which events occur with a baseline frequency based on historical usage to train the model. However, this score is more subjective and may be related specifically to the type of event rather than just the frequency of its occurrence. Events that require higher levels of authorization or that have more severe consequences for misuse may be generally score higher. These events are less likely to be performed by regular users.

The activity score database may be based at least in part on administrator input that characterizes certain events. For example, events related to starting a new virtual cloud network (VCN) may have a higher score based on an administrator's knowledge that such an event should be rarely used and only performed by authorized users. In some embodiments, the activity score database may also be generated and refined automatically using a machine learning algorithm. Based on feedback received after generating alerts, the activity score database may be adjusted to be more likely to correctly characterize event scores. For example, if a false alert is generated based on an event score, the corresponding activity score in the activity score database may be increased, while anomalies that go undetected may result in an event score being decreased. A neural network may be used to represent the value of the activity score where the output of the neural network is refined over time to adjust dynamically to current characterizations of that activity.

The score database may be stored as a score table. The scores may be generated internally by a machine learning algorithm that scores activities based on their relative frequency across a number of users. Some embodiments may also receive scores as assigned by an administrator. In some embodiments, scores may range from a value of 0 representing the baseline score for the baseline threshold described above and a value of 100 representing the upper threshold also described above. Thus, the activity score in the activity score database further characterizes an event score as being an actionable anomaly between these two thresholds. An example of a score database or score table is illustrated below in Table 1. Note that this is a small subset of the possible actions that may be in a score table. In practice, the score table may include may more actions with associated scores.

TABLE 1 Action Score DlpRuleMatch 80 FileMalwareDetected 99 Update application. 60 Update 17 New-MailContact 20 New-TransportRule 60 Remove app role assignment from user. 15 SiteDeleted 70 AccessRequestApproved 65 Change user password. 60 Disable account. 65 New-AdminAuditLogSearch 60 RemovedFrom SecureLink 55 Set-AcceptedDomain 12 CommentDeleted 10

If the score of the particular anomalous action is above a predetermined threshold at step 510 that is determined by the activity score database, an alert can be generated at step 512. The predetermined threshold may be generated in a number of different ways. In some embodiments, the threshold may be statically set. For example, any anomalous action with the score over 75 may be flagged to generate an alert. In some embodiments, a score of the action may be compared to scores of other actions performed in the past. For example, if the anomalous action had a score of 90, but the user periodically performs actions in the past with similar high scores, then it may be assumed that the user has a higher privilege level that allows those high-score actions to be executed. Therefore, even if performed rarely, these high-score actions need not generate an alert because they have been previously performed for that user on a regular, even if infrequent basis.

At step 512, an alert may be generated that describes the action taken as an anomaly and may provide additional information to the customer cloud environment. For example, the method may be executed using Python and various code libraries running on a Linux node using Ubuntu 16 or higher in the cloud. These code files may be triggered by a shell script to read in a dictionary file of user actions and daily input files received from the various customer cloud environments. These daily input sets may be analyzed as described above to generate anomaly alerts and explanation files in, for example, a CSV format. Additionally, a user interface may display the alerts and/or explanations for the cloud environment administrators. If no alerts are generated, then the analysis can continue for the next time interval at step 514.

It should be appreciated that the specific steps illustrated in FIGS. 5A and 5B provide particular methods of detecting anomalous user behavior in a cloud environment according to various embodiments of the present invention. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in FIGS. 5A and 5B may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

Outliers In Low Score Levels

In some embodiments, a method may combine a knowledge based filter with the computed scores of the mean and standard deviation values of all corresponding action counts among all cloud users across entire cloud tenants. This method furthers the unsupervised learning techniques described above to differentiate itself from existing clustering methods (K-Mean, Nearest Neighbor, etc.). This technique is configured to identify outliers that would not otherwise qualify as anomalies using the algorithms above. For example, actions taken by users that are well within their assumed privilege level not be identified as anomalies. However, even actions that are taken within their privilege level can be of concern to a client. When a user takes far more of a particular type of action than normal, this may be cause for concern. For example, a user sending thousands more emails than normal may indicate corporate espionage or denial of service attacks.

FIG. 6A illustrates two data vectors describing user actions, according to some embodiments. The first vector 402 represents the average actions taken over the previous 90 day window 408. The second vectors 604 represents actions taken during a current day 602. Note that all of the action counts from the current day 602 are within an acceptable range of the average action counts from the 90 day window 408 except for email actions 604. On the current day 602, the number of emails sent has increased by more than a factor of 10. Although the algorithms above may not identify email actions 604 as an outlier since they are normally approved for this user's privilege level, the total number as an outlier may be of concern.

Recall that in the process described above in relation to the flowcharts of FIGS. 5A-5B, the method compared a vector of actions from the current time interval with a vector of actions that are averaged over a sliding activity window. The similarity score described above is able to detect an overall pattern of suspicious behavior from a single user or against a single resource/application. That process treated each action count in the vector as a coordinate in an N-degree space, then used a similarity measure (e.g., a cosine similarity measure) to determine the similarity of the two vectors. This vector similarity acted as a proxy for considering the actions together as a whole. Thus, this process is able to detect deviations in overall patterns of actions that may be missed by comparing individual actions to averages or thresholds.

However, the process described above in relation to the flowcharts of FIGS. 5A-5B may miss individual outliers that signal suspicious behavior in a single action category. Since the similarity measure compares the similarity of two vectors in their entirety, individual coordinates in the vector representing individual actions in the collection of actions may be missed. For example, a single outlier action, such as the email actions 604 in FIG. 6 may be “smoothed” when mixed in with the similarity of the rest of the actions in the action vector. Therefore, some embodiments may detect individual outlier actions in addition to detecting an overall similarity in an action vector. The individual outliers may be detected by comparison to the sliding activity window, by comparison to average action counts across a single tenant, by comparison to average action counts across multiple tenants, by comparison to average action counts across multiple cloud environments, and/or by comparison to any other peer group.

FIG. 6B illustrates a method for detecting individual outliers in comparison to a sliding activity window for a single object, according to some embodiments. As described above, the single object in this method may represent a user, a resource, an application, and/or any other object to which actions may be attributed in the cloud environment. The method in flowchart 600 illustrates how the actions in the current time interval may be compared to the average actions from the sliding activity window for that object.

The method may include starting at any point in the flowcharts of FIGS. 5A-5B (620). For example, this method in flowchart 600 may be executed before a similarity is calculated (504), before or after a comparison to the baseline threshold (506), before or after a comparison to the upper threshold (510), before or after an alert is generated (512), before or after accessing an activity score database (520) and/or comparing the activity score to the score from the database (522), and/or at any other point in these flowcharts. Flowchart 600 may also be executed before or after the flowcharts of FIGS. 5A-5B.

The method may also include comparing an action from the current time interval with a corresponding action from the sliding activity window (622). In some embodiments, the action from the sliding activity window may represent a mean, a mode, a median, and/or any other statistical characteristic of the action count in the sliding activity window. For simplicity, this disclosure may refer to this characterization as an “average.” However, anywhere in this disclosure that an “average” is used as an example, other embodiments may substitute the average for any other statistical measure or characterization of action counts in the sliding activity window. This comparison may be made in real time as actions are added to the action count of the current time interval. Additionally, the comparison may be made at the end of the current time interval (e.g., at the end of the day) or when receiving a batch of actions in an action log.

The method may additionally include determining whether the action count in the current time interval exceeds the statistical characterization of the action counts from the sliding activity window by more than a threshold amount (624). For example, small deviations from the average action count may be within a normal activity range. If a user sends an average of 25 emails per day during the sliding activity window, then sending 45 emails during the current day need not rise to the level of an actionable alert item. However, if the user sends 245 emails during the current day, this may exceed the average action count of the sliding activity window sufficiently to trigger an alert.

The threshold by which the action count for the current day may exceed the average action count from the sliding activity window may be set individually for each action type and may be dynamically updated at runtime. For example, some embodiments may assign different thresholds to different action types. The different thresholds may be determined based on the severity of the consequences of misusing the action. For example, using the score from the activity score database (520) from FIG. 5B, the system may inversely scale the thresholds used for each activity based on the score from this score database. Higher scores representing higher-consequence actions may reduce the threshold such that a smaller deviation from the average action count may trigger an alert.

In some embodiments, the thresholds may be represented by individual neural networks for each action type. The neural network may receive as inputs the action type and the action count for the current time interval. The output of the neural network may include at least two outputs indicating whether the action count from the current day should trigger an alert or not. Additionally, the neural network may be trained using these action count as training data sets. These data sets may later be labeled based on a response to the alert that is generated. For example, if an alert is generated and the alert is suppressed by an administrator, this data set may automatically be labeled as a “no alert” data set to train the neural network. Additionally, if an alert is generated when not detected by the neural network, this data set may be labeled as an “alert” data set to train the neural network. Alerts that are correctly determined may also be used to train the neural network.

The method may further include determining whether additional actions remain in the action vector (626). If additional actions remain, the system may move on to the next action and iterate through each of the actions until the action count for each action type in the action vector has been analyzed for outliers. For example, each individual action count from the current time interval may be compared to an action count in the activity window (622).

In some embodiments, when a single action count from the current time interval exceeds its corresponding threshold, the system may generate an alert (628). After the alert is generated, the system may then determine whether additional actions remain in the action vector (626) and then proceed to process each action individually. In other embodiments, processing may end after the alert is generated. For example, if the user/resource/application is identified as a security threat, the actions associated with that user/resource/application may be shut down, which may eliminate the need to continue analyzing the action vector for outlier anomalies. In other embodiments, alerts may be generated for each action count for the object that exceeds its corresponding threshold. Because each action may be associated with a particular type of alert or scale of different alerts, some alerts may be generated with minimal consequence, while others may shut down systems or perform other drastic remedial measures. Therefore, processing may continue (630) until an alert is generated and a remedial action is taken such that further processing becomes unnecessary.

It should be appreciated that the specific steps illustrated in FIG. 6B provide particular methods of detecting outlier behavior in a cloud environment according to various embodiments. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in FIG. 6B may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

The method described above in flowchart 600 identifies outliers by comparing actions from an object (e.g., user, resource, application) with previous actions from that same object. However, some embodiments may also combine a knowledge-based filter with computed scores from a mean and standard deviation for values of corresponding action counts from among different peer groups. As described above, these peer groups may be across a user type, across a single tenant, across a cloud environment, across multiple cloud environments, and/or may use other industry standards as a comparison baseline. As with the previous methods discussed in this disclosure, this method may be characterized as an unsupervised learning method, and may be distinguished from existing clustering methods. As described above, thresholds may be determined individually for each action and/or for each user/resource/application. These embodiments also base these thresholds on a statistical characterization of these different peer groups.

FIG. 7A illustrates equations that may be used to adjust a threshold based on a larger peer group, according to some embodiments. These equations may use a vector of action count for a particular action across a peer group. Each of the thresholds T may be dynamically calculated using equation 702. For example, the action(i) may represent a vector of action count for a single action type, were each entry in the vector represents an action count from a particular user within the peer group. The mean for the action may be calculated using the mean function, which uses the standard mathematical operations for calculating a mean from a vector of values. This function may calculate a global mean for the same action across all users i=1, 2, . . . , M in the peer group.

In addition to calculating the mean, a standard deviation may also be calculated across the peer group for a particular action. Equation 704 illustrates a method of calculating the standard deviation where N represents the number of users in the peer group, where z may represent the mean of all action counts for action(i). This may be calculated for action counts of all users who performed the same actions in previous D days (D=60˜120 with a default of 90).

Equation 702 for calculating the thresholds includes an adjustable value N that may be adjusted dynamically based on data distribution features, data bias, and covariance. In some vitamins, the value for this adjustable factor N may vary between 3 and 6.

Next, a knowledge-based filter value may be quantified by the action scale values that are defined as: S(i, action(i))=globalmean(action(i))·scalevalue(action(i))

where i=1, 2, . . . , M. The scale values may be based on the table described below. Action outliers may then be detected by these conditions: IF Count(action(i))>Threshold(i, action(i)) AND Count(action(i))>S(i, action(i)) THEN action(i) may be labeled as an outlier

where T(i, action(i)) and S(i, action(i)) may be dynamically computed based on raw data inputs from various peer groups, cloud applications, resources, and so forth.

The knowledge based filter may use a scale or numeric weights to measure the risk levels of all known actions. These numeric weights can be modified automatically by cloud real-time data and/or administrator expertise. An example of the score and weights is illustrated below in Table 2.

TABLE 2 Action Score Weight DlpRuleMatch 80 10 FileMalwareDetected 99 5 Update application. 60 20 Update 17 50 New-MailContact 20 50 New-TransportRule 60 20 Remove app role assignment from user. 15 50 SiteDeleted 70 15 AccessRequestApproved 65 20 Change user password. 60 20 Disable account. 65 20 New-AdminAuditLogSearch 60 20 RemovedFromSecureLink 55 25 Set-AcceptedDomain 12 50 CommentDeleted 10 50

Using the weights, outliers can be detected when the following two conditions are met: (1) when the detected values are larger than the multiplication of numeric numbers (representing the action risk levels) and the global mean values of the same actions across all cloud tenants and users; and (2) when the outlier filter values from Table 2 are satisfied. This method can detect the user action outliers in a given period and any single day.

FIG. 7B illustrates a flowchart 700 of a method for detecting outliers, according to some embodiments. The method may include receiving actions from across the cloud environment and/or other environments being monitored by the system (710). As described above, different peer groups may be selected such that these actions are received for users within a single tenant, users within a single cloud environment, users with a single application, actions performed against a specific resource, actions performed against a specific resource across cloud environments, and/or any other industry-standard or group that may be available.

The method may further include determining whether a first layer filter is satisfied (712). For example, the first layer filter may be implemented by determining whether the action count is greater than or equal to the global mean by at least X standard deviations above the global mean for that action count. The value for Xmay be set to be any value in different embodiments. This may act as a first-level coarse filter for detecting outlier actions. If this filter is not satisfied (e.g., if the action count is not greater than the global mean by at least X standard deviations), then it can be initially determined that the action count does not represent an outlier requiring an alert (722).

However, if the threshold is exceeded and the action count exceeds the global mean by the specified amount, then further processing may take place. In this case, the method may further include calculating a new scale table using a ratio of the action local mean over a global mean (714). The scale value described above may be recalculated by using a local mean from a local peer group. The local mean may also be calculated using the local mean of actions for this particular user/resource. The global mean may be across a larger peer group, such as across a tenant, across an application, across a cloud environment, across an industry, and so forth.

The method may also include building a new scale table by combining new action scales if the recalculated scale is above the threshold (716). This raises the scale level of various actions if the recalculation increases the scale. However, the original action scales may be used if they are below the threshold.

After recalculating and building the new scale table, the method may include determining whether a second layer filter is satisfied (718). The second layer filter may compare the action count for the user/resource to the global mean multiplied by the new action scale. If the action count exceeds this threshold, the method may output a list of outlier users and/or actions (720), and appropriate alerts may be generated as needed.

It should be appreciated that the specific steps illustrated in FIG. 7B provide particular methods of detecting outlier behavior in a cloud environment according to various embodiments. Other sequences of steps may also be performed according to alternative embodiments. For example, alternative embodiments of the present invention may perform the steps outlined above in a different order. Moreover, the individual steps illustrated in FIG. 7B may include multiple sub-steps that may be performed in various sequences as appropriate to the individual step. Furthermore, additional steps may be added or removed depending on the particular applications. One of ordinary skill in the art would recognize many variations, modifications, and alternatives.

In addition to the flowchart 700 illustrated in FIG. 7 , the following pseudocode provides an example of how this algorithm may be implemented. This pseudocode is written in the Python programming language, and illustrates one example of how this multi-layer filter approach may be executed to identify outlier actions.

PSEUDOCODE EXAMPLE

dataframe = dataframe[‘count’] >= dataframe[‘action_mean’]+3*dataframe[‘action_ stddev’] if dataframe is not empty:  dataframe[‘new_scale’] = dataframe[‘local_mean’] / dataframe[‘action_mean’]  new_scale_table = concatenation(news scale <= threshold, origin scale <= threshold)  new_dataframe = join(dataframe, new_scale_table)  new_dataframe[‘count’] >= new_dataframe[‘action_mean’]*new_dataframe[‘scale’]  if new_dataframe is not empty:   return new_dataframe as outlier  else:   print “no outlier found”

Using the pseudocode listed above, the following two examples illustrate real outputs from actual data from the Microsoft® O365 cloud application. The user data is labeled as “evntactor” in these examples. The outputs listed below provide individual outputs for each outlier action (e.g., emails sent, folder created, etc.) each outlier then illustrates historic behaviors for a selected peer group. Finally, the outputs of both filter levels (e.g., Method [1] and Method [2]) are provided. Note that in the second example, the actions are very likely caused by a bot, since it is unlikely that a human created 2,968 folders on a single day.

OUTPUT EXAMPLE 1

-   . . . evntaction, resource, count, count_per_day, level, class, days -   Outlier: (emails) Sent, Exchange-MailFlow, 5724.0, 5724.0, 5.0, All     user, 1.0 . . . (today) -   Historic behaviors: 447818.0, 4975.8, 5.0, All user, 90.0 . . .     (Previous 90 days) -   Reasons: -   Method [1] 5724 actions>Global     action_mean+3*action_std=13.868+3*204.887 -   Method [2] 5724 actions>Global action_mean*Scale=13.868*239.326

OUTPUT EXAMPLE 2

-   . . . evntaction, resource, count, count_per_day, level, class, days -   Outlier: FolderCreated, SharePoint/OneDrive-Folder, 2968.0, 2968.0,     7.0, All user, 1.0 . . . (today) -   Historic behaviors: SharePoint/OneDrive-Folder, 2918.0, 32.4, 7.0,     All user, 90.0, . . . (Previous 90 days) -   Reasons: -   Method [1] 2968 actions>Global     action_mean+3*action_std=1.924+3*22.366 -   Method [2] 2968 actions>Global action_mean*Scale=1.924*885.518

Each of the methods described herein may be implemented by a computer system. Each step of these methods may be executed automatically by the computer system, and/or may be provided with inputs/outputs involving a user. For example, a user may provide inputs for each step in a method, and each of these inputs may be in response to a specific output requesting such an input, wherein the output is generated by the computer system. Each input may be received in response to a corresponding requesting output. Furthermore, inputs may be received from a user, from another computer system as a data stream, retrieved from a memory location, retrieved over a network, requested from a web service, and/or the like. Likewise, outputs may be provided to a user, to another computer system as a data stream, saved in a memory location, sent over a network, provided to a web service, and/or the like. In short, each step of the methods described herein may be performed by a computer system, and may involve any number of inputs, outputs, and/or requests to and from the computer system which may or may not involve a user. Those steps not involving a user may be said to be performed automatically by the computer system without human intervention. Therefore, it will be understood in light of this disclosure, that each step of each method described herein may be altered to include an input and output to and from a user, or may be done automatically by a computer system without human intervention where any determinations are made by a processor. Furthermore, some embodiments of each of the methods described herein may be implemented as a set of instructions stored on a tangible, non-transitory storage medium to form a tangible software product.

FIG. 8 depicts a simplified diagram of a distributed system 800 for implementing one of the embodiments. In the illustrated embodiment, distributed system 800 includes one or more client computing devices 802, 804, 806, and 808, which are configured to execute and operate a client application such as a web browser, proprietary client (e.g., Oracle Forms), or the like over one or more network(s) 810. Server 812 may be communicatively coupled with remote client computing devices 802, 804, 806, and 808 via network 810.

In various embodiments, server 812 may be adapted to run one or more services or software applications provided by one or more of the components of the system. In some embodiments, these services may be offered as web-based or cloud services or under a Software as a Service (SaaS) model to the users of client computing devices 802, 804, 806, and/or 808. Users operating client computing devices 802, 804, 806, and/or 808 may in turn utilize one or more client applications to interact with server 812 to utilize the services provided by these components.

In the configuration depicted in the figure, the software components 818, 820 and 822 of system 800 are shown as being implemented on server 812. In other embodiments, one or more of the components of system 800 and/or the services provided by these components may also be implemented by one or more of the client computing devices 802, 804, 806, and/or 808. Users operating the client computing devices may then utilize one or more client applications to use the services provided by these components. These components may be implemented in hardware, firmware, software, or combinations thereof. It should be appreciated that various different system configurations are possible, which may be different from distributed system 800. The embodiment shown in the figure is thus one example of a distributed system for implementing an embodiment system and is not intended to be limiting.

Client computing devices 802, 804, 806, and/or 808 may be portable handheld devices (e.g., an iPhone®, cellular telephone, an iPad®, computing tablet, a personal digital assistant (PDA)) or wearable devices (e.g., a Google Glass® head mounted display), running software such as Microsoft Windows Mobile®, and/or a variety of mobile operating systems such as iOS, Windows Phone, Android, BlackBerry 10, Palm OS, and the like, and being Internet, e-mail, short message service (SMS), Blackberry®, or other communication protocol enabled. The client computing devices can be general purpose personal computers including, by way of example, personal computers and/or laptop computers running various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems. The client computing devices can be workstation computers running any of a variety of commercially-available UNIX® or UNIX-like operating systems, including without limitation the variety of GNU/Linux operating systems, such as for example, Google Chrome OS. Alternatively, or in addition, client computing devices 802, 804, 806, and 808 may be any other electronic device, such as a thin-client computer, an Internet-enabled gaming system (e.g., a Microsoft Xbox gaming console with or without a Kinect® gesture input device), and/or a personal messaging device, capable of communicating over network(s) 810.

Although exemplary distributed system 800 is shown with four client computing devices, any number of client computing devices may be supported. Other devices, such as devices with sensors, etc., may interact with server 812.

Network(s) 810 in distributed system 800 may be any type of network familiar to those skilled in the art that can support data communications using any of a variety of commercially-available protocols, including without limitation TCP/IP (transmission control protocol/Internet protocol), SNA (systems network architecture), IPX (Internet packet exchange), AppleTalk, and the like. Merely by way of example, network(s) 810 can be a local area network (LAN), such as one based on Ethernet, Token-Ring and/or the like. Network(s) 810 can be a wide-area network and the Internet. It can include a virtual network, including without limitation a virtual private network (VPN), an intranet, an extranet, a public switched telephone network (PSTN), an infra-red network, a wireless network (e.g., a network operating under any of the Institute of Electrical and Electronics (IEEE) 802.11 suite of protocols, Bluetooth®, and/or any other wireless protocol); and/or any combination of these and/or other networks.

Server 812 may be composed of one or more general purpose computers, specialized server computers (including, by way of example, PC (personal computer) servers, UNIX® servers, mid-range servers, mainframe computers, rack-mounted servers, etc.), server farms, server clusters, or any other appropriate arrangement and/or combination. In various embodiments, server 812 may be adapted to run one or more services or software applications described in the foregoing disclosure. For example, server 812 may correspond to a server for performing processing described above according to an embodiment of the present disclosure.

Server 812 may run an operating system including any of those discussed above, as well as any commercially available server operating system. Server 812 may also run any of a variety of additional server applications and/or mid-tier applications, including HTTP (hypertext transport protocol) servers, FTP (file transfer protocol) servers, CGI (common gateway interface) servers, JAVA® servers, database servers, and the like. Exemplary database servers include without limitation those commercially available from Oracle, Microsoft, Sybase, IBM (International Business Machines), and the like.

In some implementations, server 812 may include one or more applications to analyze and consolidate data feeds and/or event updates received from users of client computing devices 802, 804, 806, and 808. As an example, data feeds and/or event updates may include, but are not limited to, Twitter® feeds, Facebook® updates or real-time updates received from one or more third party information sources and continuous data streams, which may include real-time events related to sensor data applications, financial tickers, network performance measuring tools (e.g., network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like. Server 812 may also include one or more applications to display the data feeds and/or real-time events via one or more display devices of client computing devices 802, 804, 806, and 808.

Distributed system 800 may also include one or more databases 814 and 816. Databases 814 and 816 may reside in a variety of locations. By way of example, one or more of databases 814 and 816 may reside on a non-transitory storage medium local to (and/or resident in) server 812. Alternatively, databases 814 and 816 may be remote from server 812 and in communication with server 812 via a network-based or dedicated connection. In one set of embodiments, databases 814 and 816 may reside in a storage-area network (SAN). Similarly, any necessary files for performing the functions attributed to server 812 may be stored locally on server 812 and/or remotely, as appropriate. In one set of embodiments, databases 814 and 816 may include relational databases, such as databases provided by Oracle, that are adapted to store, update, and retrieve data in response to SQL-formatted commands.

FIG. 9 is a simplified block diagram of one or more components of a system environment 900 by which services provided by one or more components of an embodiment system may be offered as cloud services, in accordance with an embodiment of the present disclosure. In the illustrated embodiment, system environment 900 includes one or more client computing devices 904, 906, and 908 that may be used by users to interact with a cloud infrastructure system 902 that provides cloud services. The client computing devices may be configured to operate a client application such as a web browser, a proprietary client application (e.g., Oracle Forms), or some other application, which may be used by a user of the client computing device to interact with cloud infrastructure system 902 to use services provided by cloud infrastructure system 902.

It should be appreciated that cloud infrastructure system 902 depicted in the figure may have other components than those depicted. Further, the embodiment shown in the figure is only one example of a cloud infrastructure system that may incorporate an embodiment of the invention. In some other embodiments, cloud infrastructure system 902 may have more or fewer components than shown in the figure, may combine two or more components, or may have a different configuration or arrangement of components.

Client computing devices 904, 906, and 908 may be devices similar to those described above for 802, 804, 806, and 808.

Although exemplary system environment 900 is shown with three client computing devices, any number of client computing devices may be supported. Other devices such as devices with sensors, etc. may interact with cloud infrastructure system 902.

Network(s) 910 may facilitate communications and exchange of data between clients 904, 906, and 908 and cloud infrastructure system 902. Each network may be any type of network familiar to those skilled in the art that can support data communications using any of a variety of commercially-available protocols, including those described above for network(s) 810.

Cloud infrastructure system 902 may comprise one or more computers and/or servers that may include those described above for server 812.

In certain embodiments, services provided by the cloud infrastructure system may include a host of services that are made available to users of the cloud infrastructure system on demand, such as online data storage and backup solutions, Web-based e-mail services, hosted office suites and document collaboration services, database processing, managed technical support services, and the like. Services provided by the cloud infrastructure system can dynamically scale to meet the needs of its users. A specific instantiation of a service provided by cloud infrastructure system is referred to herein as a “service instance.” In general, any service made available to a user via a communication network, such as the Internet, from a cloud service provider's system is referred to as a “cloud service.” Typically, in a public cloud environment, servers and systems that make up the cloud service provider's system are different from the customer's own on-premises servers and systems. For example, a cloud service provider's system may host an application, and a user may, via a communication network such as the Internet, on demand, order and use the application.

In some examples, a service in a computer network cloud infrastructure may include protected computer network access to storage, a hosted database, a hosted web server, a software application, or other service provided by a cloud vendor to a user, or as otherwise known in the art. For example, a service can include password-protected access to remote storage on the cloud through the Internet. As another example, a service can include a web service-based hosted relational database and a script-language middleware engine for private use by a networked developer. As another example, a service can include access to an email software application hosted on a cloud vendor's web site.

In certain embodiments, cloud infrastructure system 902 may include a suite of applications, middleware, and database service offerings that are delivered to a customer in a self-service, subscription-based, elastically scalable, reliable, highly available, and secure manner. An example of such a cloud infrastructure system is the Oracle Public Cloud provided by the present assignee.

In various embodiments, cloud infrastructure system 902 may be adapted to automatically provision, manage and track a customer's subscription to services offered by cloud infrastructure system 902. Cloud infrastructure system 902 may provide the cloud services via different deployment models. For example, services may be provided under a public cloud model in which cloud infrastructure system 902 is owned by an organization selling cloud services (e.g., owned by Oracle) and the services are made available to the general public or different industry enterprises. As another example, services may be provided under a private cloud model in which cloud infrastructure system 902 is operated solely for a single organization and may provide services for one or more entities within the organization. The cloud services may also be provided under a community cloud model in which cloud infrastructure system 902 and the services provided by cloud infrastructure system 902 are shared by several organizations in a related community. The cloud services may also be provided under a hybrid cloud model, which is a combination of two or more different models.

In some embodiments, the services provided by cloud infrastructure system 902 may include one or more services provided under Software as a Service (SaaS) category, Platform as a Service (PaaS) category, Infrastructure as a Service (IaaS) category, or other categories of services including hybrid services. A customer, via a subscription order, may order one or more services provided by cloud infrastructure system 902. Cloud infrastructure system 902 then performs processing to provide the services in the customer's subscription order.

In some embodiments, the services provided by cloud infrastructure system 902 may include, without limitation, application services, platform services and infrastructure services. In some examples, application services may be provided by the cloud infrastructure system via a SaaS platform. The SaaS platform may be configured to provide cloud services that fall under the SaaS category. For example, the SaaS platform may provide capabilities to build and deliver a suite of on-demand applications on an integrated development and deployment platform. The SaaS platform may manage and control the underlying software and infrastructure for providing the SaaS services. By utilizing the services provided by the SaaS platform, customers can utilize applications executing on the cloud infrastructure system. Customers can acquire the application services without the need for customers to purchase separate licenses and support. Various different SaaS services may be provided. Examples include, without limitation, services that provide solutions for sales performance management, enterprise integration, and business flexibility for large organizations.

In some embodiments, platform services may be provided by the cloud infrastructure system via a PaaS platform. The PaaS platform may be configured to provide cloud services that fall under the PaaS category. Examples of platform services may include without limitation services that enable organizations (such as Oracle) to consolidate existing applications on a shared, common architecture, as well as the ability to build new applications that leverage the shared services provided by the platform. The PaaS platform may manage and control the underlying software and infrastructure for providing the PaaS services. Customers can acquire the PaaS services provided by the cloud infrastructure system without the need for customers to purchase separate licenses and support. Examples of platform services include, without limitation, Oracle Java Cloud Service (JCS), Oracle Database Cloud Service (DBCS), and others.

By utilizing the services provided by the PaaS platform, customers can employ programming languages and tools supported by the cloud infrastructure system and also control the deployed services. In some embodiments, platform services provided by the cloud infrastructure system may include database cloud services, middleware cloud services (e.g., Oracle Fusion Middleware services), and Java cloud services. In one embodiment, database cloud services may support shared service deployment models that enable organizations to pool database resources and offer customers a Database as a Service in the form of a database cloud. Middleware cloud services may provide a platform for customers to develop and deploy various business applications, and Java cloud services may provide a platform for customers to deploy Java applications, in the cloud infrastructure system.

Various different infrastructure services may be provided by an IaaS platform in the cloud infrastructure system. The infrastructure services facilitate the management and control of the underlying computing resources, such as storage, networks, and other fundamental computing resources for customers utilizing services provided by the SaaS platform and the PaaS platform.

In certain embodiments, cloud infrastructure system 902 may also include infrastructure resources 930 for providing the resources used to provide various services to customers of the cloud infrastructure system. In one embodiment, infrastructure resources 930 may include pre-integrated and optimized combinations of hardware, such as servers, storage, and networking resources to execute the services provided by the PaaS platform and the SaaS platform.

In some embodiments, resources in cloud infrastructure system 902 may be shared by multiple users and dynamically re-allocated per demand. Additionally, resources may be allocated to users in different time zones. For example, cloud infrastructure system 930 may enable a first set of users in a first time zone to utilize resources of the cloud infrastructure system for a specified number of hours and then enable the re-allocation of the same resources to another set of users located in a different time zone, thereby maximizing the utilization of resources.

In certain embodiments, a number of internal shared services 932 may be provided that are shared by different components or modules of cloud infrastructure system 902 and by the services provided by cloud infrastructure system 902. These internal shared services may include, without limitation, a security and identity service, an integration service, an enterprise repository service, an enterprise manager service, a virus scanning and white list service, a high availability, backup and recovery service, service for enabling cloud support, an email service, a notification service, a file transfer service, and the like.

In certain embodiments, cloud infrastructure system 902 may provide comprehensive management of cloud services (e.g., SaaS, PaaS, and IaaS services) in the cloud infrastructure system. In one embodiment, cloud management functionality may include capabilities for provisioning, managing and tracking a customer's subscription received by cloud infrastructure system 902, and the like.

In one embodiment, as depicted in the figure, cloud management functionality may be provided by one or more modules, such as an order management module 920, an order orchestration module 922, an order provisioning module 924, an order management and monitoring module 926, and an identity management module 928. These modules may include or be provided using one or more computers and/or servers, which may be general purpose computers, specialized server computers, server farms, server clusters, or any other appropriate arrangement and/or combination.

In exemplary operation 934, a customer using a client device, such as client device 904, 906 or 908, may interact with cloud infrastructure system 902 by requesting one or more services provided by cloud infrastructure system 902 and placing an order for a subscription for one or more services offered by cloud infrastructure system 902. In certain embodiments, the customer may access a cloud User Interface (UI), cloud UI 912, cloud UI 914 and/or cloud UI 916 and place a subscription order via these UIs. The order information received by cloud infrastructure system 902 in response to the customer placing an order may include information identifying the customer and one or more services offered by the cloud infrastructure system 902 that the customer intends to subscribe to.

After an order has been placed by the customer, the order information is received via the cloud UIs, 912, 914 and/or 916.

At operation 936, the order is stored in order database 918. Order database 918 can be one of several databases operated by cloud infrastructure system 918 and operated in conjunction with other system elements.

At operation 938, the order information is forwarded to an order management module 920. In some instances, order management module 920 may be configured to perform billing and accounting functions related to the order, such as verifying the order, and upon verification, booking the order.

At operation 940, information regarding the order is communicated to an order orchestration module 922. Order orchestration module 922 may utilize the order information to orchestrate the provisioning of services and resources for the order placed by the customer. In some instances, order orchestration module 922 may orchestrate the provisioning of resources to support the subscribed services using the services of order provisioning module 924.

In certain embodiments, order orchestration module 922 enables the management of business processes associated with each order and applies business logic to determine whether an order should proceed to provisioning. At operation 942, upon receiving an order for a new subscription, order orchestration module 922 sends a request to order provisioning module 924 to allocate resources and configure those resources needed to fulfill the subscription order. Order provisioning module 924 enables the allocation of resources for the services ordered by the customer. Order provisioning module 924 provides a level of abstraction between the cloud services provided by cloud infrastructure system 900 and the physical implementation layer that is used to provision the resources for providing the requested services. Order orchestration module 922 may thus be isolated from implementation details, such as whether or not services and resources are actually provisioned on the fly or pre-provisioned and only allocated/assigned upon request.

At operation 944, once the services and resources are provisioned, a notification of the provided service may be sent to customers on client devices 904, 906 and/or 908 by order provisioning module 924 of cloud infrastructure system 902.

At operation 946, the customer's subscription order may be managed and tracked by an order management and monitoring module 926. In some instances, order management and monitoring module 926 may be configured to collect usage statistics for the services in the subscription order, such as the amount of storage used, the amount data transferred, the number of users, and the amount of system up time and system down time.

In certain embodiments, cloud infrastructure system 900 may include an identity management module 928. Identity management module 928 may be configured to provide identity services, such as access management and authorization services in cloud infrastructure system 900. In some embodiments, identity management module 928 may control information about customers who wish to utilize the services provided by cloud infrastructure system 902. Such information can include information that authenticates the identities of such customers and information that describes which actions those customers are authorized to perform relative to various system resources (e.g., files, directories, applications, communication ports, memory segments, etc.) Identity management module 928 may also include the management of descriptive information about each customer and about how and by whom that descriptive information can be accessed and modified.

FIG. 10 illustrates an exemplary computer system 1000, in which various embodiments of the present invention may be implemented. The system 1000 may be used to implement any of the computer systems described above. As shown in the figure, computer system 1000 includes a processing unit 1004 that communicates with a number of peripheral subsystems via a bus subsystem 1002. These peripheral subsystems may include a processing acceleration unit 1006, an I/O subsystem 1008, a storage subsystem 1018 and a communications subsystem 1024. Storage subsystem 1018 includes tangible computer-readable storage media 1022 and a system memory 1010.

Bus subsystem 1002 provides a mechanism for letting the various components and subsystems of computer system 1000 communicate with each other as intended. Although bus subsystem 1002 is shown schematically as a single bus, alternative embodiments of the bus subsystem may utilize multiple buses. Bus subsystem 1002 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. For example, such architectures may include an Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnect (PCI) bus, which can be implemented as a Mezzanine bus manufactured to the IEEE P1386.1 standard.

Processing unit 1004, which can be implemented as one or more integrated circuits (e.g., a conventional microprocessor or microcontroller), controls the operation of computer system 1000. One or more processors may be included in processing unit 1004. These processors may include single core or multicore processors. In certain embodiments, processing unit 1004 may be implemented as one or more independent processing units 1032 and/or 1034 with single or multicore processors included in each processing unit. In other embodiments, processing unit 1004 may also be implemented as a quad-core processing unit formed by integrating two dual-core processors into a single chip.

In various embodiments, processing unit 1004 can execute a variety of programs in response to program code and can maintain multiple concurrently executing programs or processes. At any given time, some or all of the program code to be executed can be resident in processor(s) 1004 and/or in storage subsystem 1018. Through suitable programming, processor(s) 1004 can provide various functionalities described above. Computer system 1000 may additionally include a processing acceleration unit 1006, which can include a digital signal processor (DSP), a special-purpose processor, and/or the like.

I/O subsystem 1008 may include user interface input devices and user interface output devices. User interface input devices may include a keyboard, pointing devices such as a mouse or trackball, a touchpad or touch screen incorporated into a display, a scroll wheel, a click wheel, a dial, a button, a switch, a keypad, audio input devices with voice command recognition systems, microphones, and other types of input devices. User interface input devices may include, for example, motion sensing and/or gesture recognition devices such as the Microsoft Kinect® motion sensor that enables users to control and interact with an input device, such as the Microsoft Xbox® 360 game controller, through a natural user interface using gestures and spoken commands. User interface input devices may also include eye gesture recognition devices such as the Google Glass® blink detector that detects eye activity (e.g., ‘blinking’ while taking pictures and/or making a menu selection) from users and transforms the eye gestures as input into an input device (e.g., Google Glass®). Additionally, user interface input devices may include voice recognition sensing devices that enable users to interact with voice recognition systems (e.g., Siri® navigator), through voice commands.

User interface input devices may also include, without limitation, three dimensional (3D) mice, joysticks or pointing sticks, gamepads and graphic tablets, and audio/visual devices such as speakers, digital cameras, digital camcorders, portable media players, webcams, image scanners, fingerprint scanners, barcode reader 3D scanners, 3D printers, laser rangefinders, and eye gaze tracking devices. Additionally, user interface input devices may include, for example, medical imaging input devices such as computed tomography, magnetic resonance imaging, position emission tomography, medical ultrasonography devices. User interface input devices may also include, for example, audio input devices such as MIDI keyboards, digital musical instruments and the like.

User interface output devices may include a display subsystem, indicator lights, or non-visual displays such as audio output devices, etc. The display subsystem may be a cathode ray tube (CRT), a flat-panel device, such as that using a liquid crystal display (LCD) or plasma display, a projection device, a touch screen, and the like. In general, use of the term “output device” is intended to include all possible types of devices and mechanisms for outputting information from computer system 1000 to a user or other computer. For example, user interface output devices may include, without limitation, a variety of display devices that visually convey text, graphics and audio/video information such as monitors, printers, speakers, headphones, automotive navigation systems, plotters, voice output devices, and modems.

Computer system 1000 may comprise a storage subsystem 1018 that comprises software elements, shown as being currently located within a system memory 1010. System memory 1010 may store program instructions that are loadable and executable on processing unit 1004, as well as data generated during the execution of these programs.

Depending on the configuration and type of computer system 1000, system memory 1010 may be volatile (such as random access memory (RAM)) and/or non-volatile (such as read-only memory (ROM), flash memory, etc.) The RAM typically contains data and/or program modules that are immediately accessible to and/or presently being operated and executed by processing unit 1004. In some implementations, system memory 1010 may include multiple different types of memory, such as static random access memory (SRAM) or dynamic random access memory (DRAM). In some implementations, a basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computer system 1000, such as during start-up, may typically be stored in the ROM. By way of example, and not limitation, system memory 1010 also illustrates application programs 1012, which may include client applications, Web browsers, mid-tier applications, relational database management systems (RDBMS), etc., program data 1014, and an operating system 1016. By way of example, operating system 1016 may include various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems, a variety of commercially-available UNIX® or UNIX-like operating systems (including without limitation the variety of GNU/Linux operating systems, the Google Chrome® OS, and the like) and/or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® 10 OS, and Palm® OS operating systems.

Storage subsystem 1018 may also provide a tangible computer-readable storage medium for storing the basic programming and data constructs that provide the functionality of some embodiments. Software (programs, code modules, instructions) that when executed by a processor provide the functionality described above may be stored in storage subsystem 1018. These software modules or instructions may be executed by processing unit 1004. Storage subsystem 1018 may also provide a repository for storing data used in accordance with the present invention.

Storage subsystem 1000 may also include a computer-readable storage media reader 1020 that can further be connected to computer-readable storage media 1022. Together and, optionally, in combination with system memory 1010, computer-readable storage media 1022 may comprehensively represent remote, local, fixed, and/or removable storage devices plus storage media for temporarily and/or more permanently containing, storing, transmitting, and retrieving computer-readable information.

Computer-readable storage media 1022 containing code, or portions of code, can also include any appropriate media known or used in the art, including storage media and communication media, such as but not limited to, volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage and/or transmission of information. This can include tangible computer-readable storage media such as RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disk (DVD), or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or other tangible computer readable media. This can also include nontangible computer-readable media, such as data signals, data transmissions, or any other medium which can be used to transmit the desired information and which can be accessed by computing system 1000.

By way of example, computer-readable storage media 1022 may include a hard disk drive that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive that reads from or writes to a removable, nonvolatile magnetic disk, and an optical disk drive that reads from or writes to a removable, nonvolatile optical disk such as a CD ROM, DVD, and Blu-Ray® disk, or other optical media. Computer-readable storage media 1022 may include, but is not limited to, Zip® drives, flash memory cards, universal serial bus (USB) flash drives, secure digital (SD) cards, DVD disks, digital video tape, and the like. Computer-readable storage media 1022 may also include, solid-state drives (SSD) based on non-volatile memory such as flash-memory based SSDs, enterprise flash drives, solid state ROM, and the like, SSDs based on volatile memory such as solid state RAM, dynamic RAM, static RAM, DRAM-based SSDs, magnetoresistive RAM (MRAM) SSDs, and hybrid SSDs that use a combination of DRAM and flash memory based SSDs. The disk drives and their associated computer-readable media may provide non-volatile storage of computer-readable instructions, data structures, program modules, and other data for computer system 1000.

Communications subsystem 1024 provides an interface to other computer systems and networks. Communications subsystem 1024 serves as an interface for receiving data from and transmitting data to other systems from computer system 1000. For example, communications subsystem 1024 may enable computer system 1000 to connect to one or more devices via the Internet. In some embodiments communications subsystem 1024 can include radio frequency (RF) transceiver components for accessing wireless voice and/or data networks (e.g., using cellular telephone technology, advanced data network technology, such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.11 family standards, or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and/or other components. In some embodiments communications subsystem 1024 can provide wired network connectivity (e.g., Ethernet) in addition to or instead of a wireless interface.

In some embodiments, communications subsystem 1024 may also receive input communication in the form of structured and/or unstructured data feeds 1026, event streams 1028, event updates 1030, and the like on behalf of one or more users who may use computer system 1000.

By way of example, communications subsystem 1024 may be configured to receive data feeds 1026 in real-time from users of social networks and/or other communication services such as Twitter® feeds, Facebook® updates, web feeds such as Rich Site Summary (RSS) feeds, and/or real-time updates from one or more third party information sources.

Additionally, communications subsystem 1024 may also be configured to receive data in the form of continuous data streams, which may include event streams 1028 of real-time events and/or event updates 1030, that may be continuous or unbounded in nature with no explicit end. Examples of applications that generate continuous data may include, for example, sensor data applications, financial tickers, network performance measuring tools (e.g. network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like.

Communications subsystem 1024 may also be configured to output the structured and/or unstructured data feeds 1026, event streams 1028, event updates 1030, and the like to one or more databases that may be in communication with one or more streaming data source computers coupled to computer system 1000.

Computer system 1000 can be one of various types, including a handheld portable device (e.g., an iPhone® cellular phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a PC, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system.

Due to the ever-changing nature of computers and networks, the description of computer system 1000 depicted in the figure is intended only as a specific example. Many other configurations having more or fewer components than the system depicted in the figure are possible. For example, customized hardware might also be used and/or particular elements might be implemented in hardware, firmware, software (including applets), or a combination. Further, connection to other computing devices, such as network input/output devices, may be employed. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments.

In the foregoing description, for the purposes of explanation, numerous specific details were set forth in order to provide a thorough understanding of various embodiments of the present invention. It will be apparent, however, to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form.

The foregoing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the foregoing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing an exemplary embodiment. It should be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.

Specific details are given in the foregoing description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that the embodiments may be practiced without these specific details. For example, circuits, systems, networks, processes, and other components may have been shown as components in block diagram form in order not to obscure the embodiments in unnecessary detail. In other instances, well-known circuits, processes, algorithms, structures, and techniques may have been shown without unnecessary detail in order to avoid obscuring the embodiments.

Also, it is noted that individual embodiments may have beeen described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may have described the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in a figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination can correspond to a return of the function to the calling function or the main function.

The term “computer-readable medium” includes, but is not limited to portable or fixed storage devices, optical storage devices, wireless channels and various other mediums capable of storing, containing, or carrying instruction(s) and/or data. A code segment or machine-executable instructions may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc., may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium. A processor(s) may perform the necessary tasks.

In the foregoing specification, aspects of the invention are described with reference to specific embodiments thereof, but those skilled in the art will recognize that the invention is not limited thereto. Various features and aspects of the above-described invention may be used individually or jointly. Further, embodiments can be utilized in any number of environments and applications beyond those described herein without departing from the broader spirit and scope of the specification. The specification and drawings are, accordingly, to be regarded as illustrative rather than restrictive.

Additionally, for the purposes of illustration, methods were described in a particular order. It should be appreciated that in alternate embodiments, the methods may be performed in a different order than that described. It should also be appreciated that the methods described above may be performed by hardware components or may be embodied in sequences of machine-executable instructions, which may be used to cause a machine, such as a general-purpose or special-purpose processor or logic circuits programmed with the instructions to perform the methods. These machine-executable instructions may be stored on one or more machine readable mediums, such as CD-ROMs or other type of optical disks, floppy diskettes, ROMs, RAMs, EPROMs, EEPROMs, magnetic or optical cards, flash memory, or other types of machine-readable mediums suitable for storing electronic instructions. Alternatively, the methods may be performed by a combination of hardware and software. 

What is claimed is:
 1. A method of detecting anomalous user behavior in cloud environments, the method comprising: receiving a count of an action taken during a current time interval in a cloud environment; accessing a history of previous counts of the action taken across a peer group and generating a statistical characterization of the previous counts of the action based on a sliding window of the history of previous counts of the action across the peer group; performing a first determination of whether the count of the action taken during the current time interval is greater by more than a threshold amount than the statistical characterization of the previous counts of the action taken across the peer group; calculating a scale factor as a ratio of a local mean of action counts over a global mean of action counts; performing a second determination of whether the count of the action is greater than the global mean of action counts multiplied by the scale factor for the action; determining that the action represents an outlier based on the first determination and the second determination; and generating an alert based on determining that the action represents an outlier.
 2. The method of claim 1, wherein the count of the action taken during the current time interval comprises a count of a single action type performed by a single user.
 3. The method of claim 1, wherein the count of the action taken during the current time interval comprises a count of a single action type performed on a single resource.
 4. The method of claim 1, further comprising generating the count of the action taken during the current time interval by aggregating actions by a single user or on a single resource from an action log recorded during the current time interval.
 5. The method of claim 1, wherein the threshold amount comprises a predetermined number of standard deviations above the statistical characterization of the previous times when the action was taken across the peer group.
 6. The method of claim 1, wherein determining whether the count of the action is greater by more than a threshold amount comprises: providing the count of the action and a type of the action to a neural network; and receiving an output from the neural network indicating whether the action represents an outlier.
 7. The method of claim 6, wherein the neural network is trained using the count of the action, the type of the action, and a response to the alert.
 8. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising: receiving a count of an action taken during a current time interval in a cloud environment; accessing a history of previous counts of the action taken across a peer group and generating a statistical characterization of the previous counts of the action based on a sliding window of the history of previous counts of the action across the peer group; performing a first determination of whether the count of the action taken during the current time interval is greater by more than a threshold amount than the statistical characterization of the previous counts of the action taken across the peer group; calculating a scale factor as a ratio of a local mean of action counts over a global mean of action counts; performing a second determination of whether the count of the action is greater than the global mean of action counts multiplied by the scale factor for the action; determining that the action represents an outlier based on the first determination and the second determination; and generating an alert based on determining that the action represents an outlier.
 9. The non-transitory computer-readable medium of claim 8, wherein the operations further comprise: calculating a first vector that is representative of actions taken during a plurality of previous time intervals in the cloud environment; calculating a similarity between the first vector and a second vector that comprises counts of actions taken during a current time interval, wherein the second vector also comprises the count of the action; comparing the similarity to a baseline threshold to determine whether one or more anomalous actions have occurred; and generating an alert based at least in part on a determination that the one or more anomalous actions have occurred in the cloud environment.
 10. The non-transitory computer-readable medium of claim 9, wherein the similarity is calculated using a cosine similarity.
 11. The non-transitory computer-readable medium of claim 9, wherein each entry in the first vector comprises an average event score during the plurality of previous time intervals.
 12. The non-transitory computer-readable medium of claim 9, wherein each of the plurality of previous time intervals comprises one day.
 13. The non-transitory computer-readable medium of claim 9, wherein the plurality of previous time intervals comprises a sliding window of days, wherein the sliding window of days adds the current time interval to the sliding window of days and removes a least-recent time interval from the sliding window of days after each time interval.
 14. The non-transitory computer-readable medium of claim 9, wherein the first vector is representative of actions taken during the plurality of previous time intervals by storing a histogram of event counts for each of the plurality of previous time intervals.
 15. A system comprising: one or more processors; and one or more memory devices comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform operations comprising: receiving a count of an action taken during a current time interval in a cloud environment; accessing a history of previous counts of the action taken across a peer group and generating a statistical characterization of the previous counts of the action based on a sliding window of the history of previous counts of the action across the peer group; performing a first determination of whether the count of the action taken during the current time interval is greater by more than a threshold amount than the statistical characterization of the previous counts of the action taken across the peer group; calculating a scale factor as a ratio of a local mean of action counts over a global mean of action counts; performing a second determination of whether the count of the action is greater than the global mean of action counts multiplied by the scale factor for the action; determining that the action represents an outlier based on the first determination and the second determination; and generating an alert based on determining that the action represents an outlier.
 16. The system of claim 15, wherein determining whether the action represents an outlier comprises: replacing an existing scale factor for the action when the scale factor is greater than the existing scale factor.
 17. The system of claim 15, wherein the action comprises a number of emails that are sent by a particular user.
 18. The system of claim 15, wherein the action comprises a number of folders created by a particular user.
 19. The system of claim 15, wherein the operations further comprise: calculating a first vector that is representative of actions taken during a plurality of previous time intervals in the cloud environment; calculating a similarity between the first vector and a second vector that comprises counts of actions taken during a current time interval, wherein the second vector also comprises the count of the action; comparing the similarity to a baseline threshold to determine whether one or more anomalous actions have occurred; and generating an alert based at least in part on a determination that the one or more anomalous actions have occurred in the cloud environment.
 20. The system of claim 15, wherein determining whether the count of the action is greater by more than a threshold amount comprises: providing the count of the action and a type of the action to a neural network; and receiving an output from the neural network indicating whether the action represents an outlier. 